Extraocular and intraocular slit beam illuminators are known and used in office and surgical settings for illuminating ocular structures, such as the cornea and lens surfaces and intraocular fluids and tissues including retina and vitreous. These structures, which are nearly-transparent, are difficult to distinguish using conventional illumination due to the small amount of light scatter which they produce when diffusely lit. The use of a slit-shaped beam allows selective, directed, and intense illumination of nearly-transparent tissues such that even a relatively small amount of scatter by such tissues allows them to be distinguished and otherwise observed or targeted for surgical modification or removal. The slit-illumination also provides a sense of depth, thickness, and three-dimensions to these transparent structures, especially when applied obliquely.
U.S. Pat. Nos. 6,080,143 and 5,630,809, commonly invented by the inventor of the present application and incorporated herein by reference, describe surgical illumination systems for providing illumination of intraocular target structures within an eye during surgical procedures for diagnosis or treatment of ocular conditions. The disclosed systems include an intraocular instrument having a distal end capable of insertion into the eye, the intraocular instrument having a light-conductor for transmitting a light beam, and a mask or other means for forming the light beam into a slit-shaped beam. The slit-shaped beam is emitted from the distal end of the instrument when the instrument is inserted into the eye such that intraocular slit-beam illumination of target structures is provided within the eye.
One drawback of conventional intraocular illuminators is that light directed into the eye from such illuminators is reflected off/from/through the patient's cornea/lens/retina or intraocular instruments, into the eyes of the surgeon, creating glare and lessening the quality/quantity of the illumination to target tissues.